As a chassis dynamometer control device, such a configuration as disclosed in a Patent Document 1 (FIG. 4) has been known as a well-known art. FIG. 5 is a block diagram of a running resistance control device of the chassis dynamometer. Driving wheels of a test vehicle 1 are placed on a roller 2 of the chassis dynamometer, and a torque produced by a dynamometer 3 is provided, as a load, to the test vehicle 1 through the roller 2.
In order for the test vehicle 1 on the chassis dynamometer to run in the same condition as that on the road, it is necessary to provide the vehicle (a tire surface) with the same load as that when running on the road. To add the running resistance equivalent to that on the road to the tire surface with the driving wheels of the test vehicle 1 placed on a roller surface of the chassis dynamometer, a running resistance obtained by taking account of a vehicle mechanical loss FS and a chassis dynamo mechanical loss FML is provided to the tire surface. A running resistance setting section 4 generates a running resistance setting value FS according to a vehicle speed of the test vehicle A mechanical loss setting section (a chassis dynamo mechanical loss setting section) 5 generates the chassis dynamo mechanical loss FML according to the vehicle speed of the test vehicle 1. A power control command of a controller section 6 is set by subtracting the chassis dynamo mechanical loss FML from the running resistance setting value FS, and the controller section 6 performs a power absorption control of the dynamometer 3 that is mechanically connected to the roller 2.
More specifically, a vehicle speed signal of the test vehicle 1, which is detected by a speed detector 7, is inputted to the running resistance setting section 4 and the mechanical loss setting section (the chassis dynamo mechanical loss setting section) 5, and the running resistance setting value FS according to the vehicle speed and the mechanical loss FML according to the vehicle speed are calculated. A difference signal between both of the running resistance setting value FS and the mechanical loss FML is determined at a subtracting section, then the power absorption control of the dynamometer 3 is performed through the controller 6 of the chassis dynamometer. Upon performing this control, the vehicle speed detected by the speed detector 7 and a torque detected by a load cell 8 are each fed back to the controller 6.
Meanwhile, as for a technique of verifying whether inertia corresponding to the test vehicle is closely simulated using a result of measured mechanical loss etc., a technique as disclosed in a Patent Document 2 has been known. As a manner of verification of an inertia control in the chassis dynamometer, after a warm-up operation of the chassis dynamometer is performed within a test speed range, a mechanical loss of a unit of the chassis dynamometer is measured for each speed. This measured mechanical loss is determined as a function of the speed for the following correction data of a measurement mechanical loss of the chassis dynamometer. After completion of these preparations, the chassis dynamometer is set as a torque control mode, and an inertia value required for the mode is set, then the chassis dynamometer is accelerated (or decelerated) while undergoing correction by the above mechanical loss. From an acceleration of the chassis dynamometer at this time, the verification is made by the fact as to whether the simulated inertia falls within allowable error limits.